coastline

noun

coast·​line ˈkōs(t)-ˌlīn 

1

: a line that forms the boundary between the land and the ocean or a lake

2

: the outline of a coast

Examples of coastline in a Sentence

The plane flew along the eastern coastline.

Recent Examples on the Web

In Rio de Janeiro, that very scenario is playing out on their coastline. — Melissa Cristina Márquez, Forbes.com, 2 July 2026

Set the scene This resort stuns, with magical panoramic views of the northern coastline of Crete. — Condé Nast, Condé Nast Traveler, 2 July 2026

From the deck, Pawlak could see lightning illuminating the coastline like a fireworks show. — Karissa Waddick, USA Today, 1 July 2026

All year, the coastline is a unique, peaceful, and untouched place, thanks to its state park status (no one’s rolling a cooler and beach umbrella onto these rocks). — Kelsey Glennon, Southern Living, 30 June 2026

Word History

First Known Use

1856, in the meaning defined at sense 1

Rhymes for coastline

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• brucine
• byline

Kids Definition

coastline

noun

coast·​line ˈkōst-ˌlīn 

: the outline or shape of a coast